Humidity‐Enhanced NO2 Gas Sensing Using Atomically Sharp Edges in Multilayer MoS2

Ambient humidity poses a significant challenge in the development of practical room‐temperature NO 2 gas sensors. Herein, atomically precise zigzag edges are employed in multilayer MoS 2 , fabricated using electron beam lithography and anisotropic wet etching, to achieve highly sensitive and selective gas‐sensing performance, that is, humidity‐tolerant at elevated temperatures and humidity‐enhanced at room temperature under ultraviolet illumination. Notably, exposure to 2.5 parts per billion (ppb) NO 2 at 70% relative humidity under ultraviolet illumination and at room temperature resulted in a 33‐fold increase in response and a 6‐fold faster recovery compared to 0% relative humidity, leading to response values exceeding 1100%. The optimized samples demonstrate a theoretical detection limit ranging from 4 to 400 parts per trillion (ppt) NO 2 . The enhanced NO 2 sensing capabilities of MoS 2 edges have been further confirmed through first‐principles calculations. This study expands the applications of nanostructured MoS 2 and highlights its potential for detecting NO 2 at sub‐ppb levels in complex scenarios, such as high‐humidity conditions.